Question

Calculate the Ka for the following acid. Determine if it is a strong or weak acid.

HNO2(aq) dissolves in aqueous solution to form H+(aq) and NO2−(aq). At equilibrium, the concentrations of each of the
species are as follows:
[HNO2]=0.68M
[H+]=0.022M
[NO2−]=0.022M
Calculate the for the following acid. Determine if it is a strong or weak acid.
dissolves in aqueous solution to form and . At equilibrium, the concentrations of each of the species are as follows:
a) Ka=7.1×10−4; This is a weak acid because the acid is not completely dissociated in solution.
b) Ka=1405; This is a strong acid because the Ka is very large.
c) Ka=1405; This is a weak acid because the acid is not completely dissociated in solution.
d) Ka=7.1×10−4; This is a strong acid because the acid is completely dissociated in aqueous solution.

Answer 1

a) Ka= 7.1 × 10⁻⁴; This is a weak acid because the acid is not completely dissociated in solution.

Step-by-step explanation:

Step 1: Write the dissociation reaction for nitrous acid

HNO₂(aq) ⇄ H⁺(aq) and NO₂⁻(aq)

Step 2: Calculate the acid dissociation constant

Ka = [H⁺] × [NO₂⁻] / [HNO₂]

Ka = 0.022 × 0.022 / 0.68

Ka = 7.1 × 10⁻⁴

Step 3: Determine the strength of the acid

Since Ka is very small, nitrous acid is a weak acid, not completely dissociated in solution.